As the advent of the information society, there have been growing needs for various display panels for using in display devices, lighting devices, or the like. Among various types of display panel, an organic light emitting display panel is advantageous in a reduction in overall weight and thickness as an additional light source is not required. As a result, demands for the organic light emitting display panel have increased steadily.
However, when the organic light emitting display panel including an organic layer emitting light is operated, there is a problem that light extraction efficiency of the organic light emitting display panel is lowered and corresponding luminance efficiency is lowered because some of the light emitted from an organic layer cannot be emitted outside of the organic light emitting display panel, and therefore is trapped inside the organic light emitting display device.